As of 2008, there were one billion computers being used. Today, there are one billion computers that are actually connected to the internet and it is fair to say most of those have empty hard drive space. 
In 2014, 90% of all PCs and laptops are being shipped with at least 500 GB of hard drive space.
Now lets assume that every computer user in this world uses 50% of their 250 GB (granted there are people that have over 50 TB but it evens out with the low end) and that they are constantly connected to the web. These are actually rather small numbers considering almost all computers and laptops sold today have 750 to 1000 GB of storage shipped with them.
Now take those one billion people and multiply it by the 250 GB of free space they have and it gives you 250 billion GB of data, otherwise known as 250 million TB of free space.
Let's bring that to relative terms: that is 250,000 PETABYTES (1 PB = 1000 TB). Now let’s look at the top five largest data usage companies in the world :
- Facebook has 100 PB of data as of its IPO late last year
- Microsoft claims 300 PB is stored in its name
- Amazon claims it has 900 PB of data in the S3 backbone
- Dropbox says it stores 40 PB of data
- Google holds 8000 PB of data for all of its services (Drive, YouTube, Gmail etc)
These numbers are as of 2012/2013, let's total them and put them through Kryder’s law .
That means the people of the world, that are connected to the internet and pledge 250 GB of storage, could store all of Dropbox, Facebook, Amazon, Microsoft, and Google data, 26 times. The choice is yours, you can opt for a centralized, limited, and unsafe cloud storage; or you can choose Storj: the biggest, decentralized, and most secure network ever.
 “IPv6 - Why We Need a New Internet Protcol”, http://slideshow.techworld.com/3363475/ipv6--why-we-need-new-internet-protocol/8/, 2012
 “How Big is the Cloud?”, http://www.extremetech.com/computing/129183-how-big-is-the-cloud, 2012
 “Mark Kryder”, https://en.wikipedia.org/wiki/Mark_Kryder